• 지질공학
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• 제18권1호
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• pp.1-6
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• 2008

금강유역의 관측소로부터 수집된 강우자료와 지하수위자료를 분석하고 두 자료를 비교 분석하였다. 그리고 강우사상이 지하수위에 미치는 영향분석을 추계학적 기법인 이동평균법을 사용하여 지하수위와 강우이동평균값의 상관관계를 분석하였다. 지하수위는 강우의 계절적 분포를 대체로 따르며 대체로 12월 초부터 4월 말까지 낮은 지하수위를 형성한다. 7월과 8월의 풍수기에는 상대적으로 높은 지하수위를 형성한다. 선행강우를 고려하기 위한 강우이동평균값과 지하수위의 상관관계는 자료의 길이가 최소 2년 이상인 지하수위 관측소를 먼저 선정하였다. 강우와 지하수위 관측소 pair를 선정함에 있어 강우의 비균질한 분포를 고려해서 지하수위 관측소보다 상류에 인접한 강우관측소를 선정하여 두 자료를 분석하였다. 금강유역의 여러 관측소 자료를 분석한 결과 이동평균기간이 10일에서 150일 범위의 값을 가질 때 최대상관계수를 가졌다. 상관계수값은 자료의 질이나 결측기간 또는 융설이나 다른 요인에 의해 넓은 범위의 값을 가지는데 금강유역의 경우 최대 0.8886의 값을 가진다.

• 대기
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• 제18권4호
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• pp.387-395
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• 2008

The impact of horizontal resolution on a regional climate model was investigated by simulating precipitation over the Korean Peninsula. As a regional climate model, the SNURCM(Seoul National University Regional Climate Model) has 21 sigma layers and includes the NCAR CLM(National Center for Atmospheric Research Community Land Model) for land-surface model, the Grell scheme for cumulus convection, the Simple Ice scheme for explicit moisture, and the MRF(Medium-Range Forecast) scheme for PBL(Planetary Boundary Layer) processing. The SNURCM was performed with 20 km resolution for Korea and 60 km resolution for East Asia during a 20-year period (1980-1999). Although the SNURCM systematically underestimated precipitation over the Korean Peninsula, the increase of model resolution simulated more precipitation in the southern region of the Korean Peninsula, and a more accurate distribution of precipitation by reflecting the effect of topography. The increase of precipitation was produced by more detailed terrain data which has a 10 minute terrain in the 20 km resolution model compared to the 30 minute terrain in the 60 km resolution model. The increase in model resolution and more detailed terrain data played an important role in generating more precipitation over the Korean Peninsula. While the high resolution model with the same terrain data resulted in increasing of precipitation over the Korean Peninsula including the adjoining sea, the difference of the terrain data resolution only influenced the precipitation distribution of the mountainous area by increasing the amount of non-convective rain. In conclusion, the regional climate model (SNURCM) with higher resolution simulated more precipitation over the Korean Peninsula by reducing the systematic underestimation of precipitation over the Korean Peninsula.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.329-329
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• 2022

Accurate characterization of terrestrial precipitation variation from high spatial resolution satellite sensors is beneficial for urban hydrology and microscale agriculture modeling, as well as natural disasters (e.g., urban flooding) early warning. However, the widely-used top-down approach for precipitation retrieval from microwave satellites is limited in several hydrological and agricultural applications due to their coarse spatial resolution. In this research, we aim to apply a novel bottom-up method, the parameterized SM2RAIN, where precipitation can be estimated from soil moisture signals based on an inversion of water balance model, to generate high spatial resolution terrestrial precipitation estimates at 0.01º grid (roughly 1-km) from the C-band SAR Sentinel-1. This product was then tested against a common reanalysis-based precipitation data and a domestic rain gauge network from the Korean Meteorological Administration (KMA) over central South Korea, since a clear difference between climatic types (coasts and mainlands) and land covers (croplands and mixed forests) was reported in this area. The results showed that seasonal precipitation variability strongly affected the SM2RAIN performances, and the product derived from separated parameters (rainy and non-rainy seasons) outperformed that estimated considering the entire year. In addition, the product retrieved over the mainland mixed forest region showed slightly superior performance compared to that over the coastal cropland region, suggesting that the 6-day time resolution of S1 data is suitable for capturing the stable precipitation pattern in mainland mixed forests rather than the highly variable precipitation pattern in coastal croplands. Future studies suggest comparing this product to the traditional top-down products, as well as evaluating their integration for enhancing high spatial resolution precipitation over entire South Korea.

• 산업기술연구
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• 제25권B호
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• pp.27-35
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• 2005

Non-point source pollution, which is found in soil, urban area, and agricultural area, is difficult to have its amount to be estimated. Moreover, it is hard to come up with a counterplan to cope with this pollutant. Hence, the watershed of Mandae-cheon located at the upstream of Soyang Lake was chosen as our site of study. We analyzed the relationship between precipitation level of each month and pollution load in the watershed by using statistical methods: measuring BOD, T-N and T-P - which are the causes of eutrophication - in the water; and analyzing the changes in water quality caused by precipitation level of nth.

• 한국지능시스템학회논문지
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• 제24권5호
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• pp.536-541
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• 2014

기상레이더를 통해 취득된 데이터에는 지형에코, 파랑에코, 이상에코, 그리고 청천에코등이 존재한다. 각 에코는 여러 종류의 비강수에코이고, 이 비강수에코를 제거하기 위해 각 에코들의 특성을 분석하였다. 기상레이더 데이터는 매우 방대한 양이기 때문에 전처리 절차를 통해 분석된다. 본 논문에서는 클러스터링 기반 방사형 기저함수 신경회로망(RBFNNs : Radial Basis Function Neural Networks)과 에코 판단 모듈을 이용하여 기상레이더 데이터에서 강수에코와 비강수에코들을 구별하기 위한 에코 패턴분류기를 설계하였다. HCM(Hard C-Mean) 클러스터링 기반 RBFNNs 와 FCM(Fuzzy C-Mean) 클러스터링 기반 RBFNNs를 이용하여 출력성능은 비교 및 분석된다.

• 환경영향평가
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• 제20권5호
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• pp.651-661
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• 2011

The purpose of this study is to estimate the characteristics and pollutant loadings of non-point pollutants that flowed in the streams on precipitation for pollutant loading reduction of Hwa-sung lake inflow streams. Although it has been made an effort to improve the water quality of Hwa-sung basin through the strategies for the preservation of water quality, it is shown that the water quality is not greatly improved. Because it has been industrialized and urbanized near Hwa-sung basin so that it is difficult to reduce the water pollution due to the increase in pollutant loadings of point and non-point sources. In this study, it is investigated the outflow characteristics of non-point pollutants that discharged with storm runoff and estimated the effect of runoff on Hwa-sung basin. The final goal of this study is to utilize the basic information for proper management and strategies of non-point sources on Hwa-sung basin. At the result of inflow streams, Ja-an stream that has the greatest pollutant loadings on precipitation is strongly influenced on the water quantity of Hwa-sung basin. On the other hand, it is shown that Nam-yang stream is strongly influenced on the SS concentration of Hwasung basin among them. Also, all streams; Nam-yang, Ja-ahn, Ah-eun stream; has the degree of slope more than or near 1 in the correlation results so that they have strong pollutant loading impact and the concentration of SS is the highest among other pollutants. So, specific studies on initial rain phenomena are more necessary to manage the pollutants economically. Also, the proper control of SS concentration is required to manage the effluent pollutants effectively on precipitation. So, it is necessary to consider the strategies for non-point pollutants as well as point pollutants when the new management is imposed to reduce the pollutant load for improvement of Hwa-sung basin.

• 한국농공학회논문집
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• 제57권5호
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• pp.139-152
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• 2015

Along with climate change, it is reported that the scale and frequency of extreme climate events show unstable tendency of increase. Thus, to comprehend the change characteristics of precipitation data, it is needed to consider non-stationary. The main objectives of this study were to estimate future design floods for Wonpyeongcheon watershed based on RCP (Representative Concentration Pathways) scenario. Wonpyeongcheon located in the Keum River watershed was selected as the study area. Historical precipitation data of the past 35 years (1976~2010) were collected from the Jeonju meteorological station. Future precipitation data based on RCP4.5 were also obtained for the period of 2011~2100. Systematic bias between observed and simulated data were corrected using the quantile mapping (QM) method. The parameters for the bias-correction were estimated by non-parametric method. A non-stationary frequency analysis was conducted with moving average method which derives change characteristics of generalized extreme value (GEV) distribution parameters. Design floods for different durations and frequencies were estimated using rational formula. As the result, the GEV parameters (location and scale) showed an upward tendency indicating the increase of quantity and fluctuation of an extreme precipitation in the future. The probable rainfall and design flood based on non-stationarity showed higher values than those of stationarity assumption by 1.2%~54.9% and 3.6%~54.9%, respectively, thus empathizing the necessity of non-stationary frequency analysis. The study findings are expected to be used as a basis to analyze the impacts of climate change and to reconsider the future design criteria of Wonpyeongcheon watershed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.43-45
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• 2021

초단기 강수예측 시스템은 단시간 발생하는 집중호우와 같은 위험기상에 대응하기 위해 사회·경제적으로 중요하다. 최근 국내·외에서 심층신경망을 활용한 초단기 강수예측 연구가 활발히 진행되고 있다. 심층신경망을 이용한 강수예측 모델은 훈련 데이터를 만들 때 기상데이터의 구조와 종류가 복잡하고 방대하므로 기상학적 이해를 바탕으로 복잡한 전처리 과정이 필요하다. 또한, 비선형적인 패턴의 강수 현상을 예측하기 위하여 기상의 상호작용에 대한 이해를 바탕으로 입력 데이터를 구성해야 한다. 따라서 본 연구에서는 다음과 같은 접근법을 제안하고자 한다. i) 기상레이더 합성 강수장과 강수발달에 영향을 줄 수 있는 주요 인자(레이더, 지형, 온도, 등)를 훈련 데이터 구축을 위해 패턴 분석에 적합한 형태로 정제하고 이를 구조화하여 통합한다. ii) 합성곱 신경망과 합성곱 장단기 기억 신경망을 접목하여 초단기 예측 강수장을 산출한다. 2020년 강수 사례를 이용하여 제안한 모델의 정확성을 검증하였다. 제안한 모델은 비선형적인 패턴의 강수 현상을 잘 모의하였고, 강수의 규모 및 강도에 대한 예측성능이 향상되었다. 이는 강수를 동반한 초단기 위험기상의 방재에 활용할 수 있을 것으로 기대된다.

• 한국대기환경학회지
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• 제20권3호
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• pp.381-396
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• 2004

In order to understand the precipitation acidity and chemical composition of ion species in Iksan area as well as to know the difference of chemical characteristics in precipitation samples from the viewpoint of precipitation sampling method, precipitation samples were collected by wet-only automatic precipitation sampler and bulk manual precipitation sampler in Iksan, from March 2003 to August 2003. The mean pH of precipitation was 5.0. There was a little significant difference in the mean value of pH between automatic and manual sampler. However, pH values of some precipitation samples were lower in automatic sampler than in manual sampler, especially in case of precipitation samples with small rainfall for March 2003. The mean concentrations of each ions in precipitation were generally a little higher in precipitation samples collected by the manual sampler than in those collected by the automatic sampler because of accumulation of dry deposition on the surface of glass funnel installed at the manual sampler during the sampling period or no rainfall. Dominant species determining the acidity of precipitation, were N $H_4$$^{[-10]}$ and nss-C $a^{2+}$ for cations and nss-S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ for anions. The mean concentration of N $H_4$$^{+}$ and nss-C $a^{2+}$ were 31 $\mu$eq/L and 9 $\mu$eq/L for the automatic sampler and 40 ueq/L and 16 ueq/L for the manual sampler, respectively. In addition, nss-S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ were 27 $\mu$eq/L and 13 $\mu$eq/L for the automatic sampler and 32 $\mu$eq/L and 17 $\mu$eq/L for the manual sampler, respectively. Although the concentrations of the acidifying ions of nss-S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ were about 3 times higher than those for foreign pristine sites, precipitation acidity were estimated to be natural due to the neutralization reaction of the alkaline species of N $H_4$$^{+}$ and nss-C $a^{2+}$ with its higher concentrations. Considering the ratios of nss-S $O_4$$^{2-}$/N $O_4$$^{[-10]}$ nss-S $O_4$$^{2-}$, it was found that ammonium sulphate was dominant in Iksan precipitation. The major non-sea salt ions were maximum concentrations for March, but decreased with increasing of precipitation amount.on amount.

• 한국광물학회:학술대회논문집
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• 한국광물학회.한국암석학회 2001년도 공동학술발표회 논문집
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• pp.45-47
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• 2001

Jeju island is composed mainly of volcanic rocks such as basalts, trachytic andesites, tracytes, and sedimentary rocks. About 80% of Jeju soils are classified as Andisols. The amount of annual precipitation in Jeju island is about 1872mm, which is 1.5 times the annual precipitation of south Korea. There is a significant difference In amount of precipitation with regions even within Jeju island. In study area, the annual amount of rainfall is about 1280mm, the lowest in Jeju island while south part of the island has the annual precipitation of 2056mm, though they are only tens of kilometers apart. The parent materials of soils in study area are pyroclastic rocks and tuffs. The soils of non-andic properties have developed in this area since pedogenic process of pyroclastic materials is strongly influenced by climatic factor, especially precipitation. In order to investigate the mineralogical characteristics of soils, X-ray analysis for <0.2 and 2-0.2$\mu\textrm{m}$ size fractions was performed with ethylene glycol solvation, K-, Mg-saturation, heat treatment(110, 330, 550$^{\circ}C$). Acid-oxalate and DCB(sodium hydrosulfite, sodium citrate, sodium bicarbonate) dissolution method was used to assess tile total amounts or Al, si, and hydroxy interlayer or 2:1 layer silicates. XRD was also applied for samples treated with DCB only and DCB-oxalate sequentially. XRD patterns showed that 2:1 and 1:1 layer silicates were found, which are different from soils of Andisols. Vermiculite, chlorite, hydroxy interlayered minreals, and interstratified minerals(vermiculite/chlorite) were observed in 2-0.2$\mu\textrm{m}$ size fractions. After DCB treatments, ethylene glycolated samples with Mg-saturation showed expanded d-spacing, suggesting the possibility of hydroxy interlayered minerals. The amounts of hydroxy interlayered minerals increased in surface soil. Unlike Andisols, short range ordered minerals such as allophane, imogolite and gibbsite were hardly found. Mica and kaolinte existed in small amounts. Results are summarized in Fig 1 and Fig. 2.